Browsing by Author "Kapilan, N."

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A comprehensive review on evaporative cooling systems
(Elsevier B.V., 2023) Kapilan, N.; Isloor, A.M.; Karinka, S.
The evaporative cooling system (ECS) is one of the cheapest and oldest cooling technologies. The conventional single stage ECS is most widely used in domestic application, particularly in hot and dry regions. However, in this system, the temperature of the air cannot be reduced below the wet bulb temperature of the air. The multistage ECS system helps to overcome this problem. The combination of direct and indirect ECS helps to reduce the temperature of the air below its wet bulb temperature. The further reduction in air temperature may be achieved with the help of the cooling coil driven by vapour compression system. The energy consumed by the ECS is lower as compared to vapour compression refrigeration system. The ECS can be driven with the help of solar power. The conventional cooling pad used in ECS can be replaced with locally available natural fibers to reduce initial cost and to reduce dependence on import of cooling pads. The performance of the ECS can be improved with the help of heat pipe. Various techniques are used to enhance ECS's performance. The performance of the vapour compression refrigeration system can be improved with the help of ECS. This paper discusses basics and types of ECS, methods used to increase the performance of ECS, types of natural fiber cooling pad material, process variables affecting ECS, recent technical advancements, challenges and opportunities. © 2023 The Authors
An experimental and numerical study on effects of exhaust gas temperature and flow rate on deposit formation in Urea-Selective Catalytic Reduction (SCR) system of modern automobiles
(Elsevier Ltd, 2017) Prabhu S, S.; Nayak, N.S.; Kapilan, N.; Hindasageri, V.
Urea Water Solution (UWS) is injected to generate NH3 in Selective Catalytic Reduction (SCR) system of modern automobiles. Thermal and fluid dynamic conditions such as temperature and Reynolds number of the flow favors ammonia generation in terms of heat transfer to UWS droplets by forced convection. During extremely cold weather conditions and low exhaust temperatures, the overdosing of UWS results in deposits of urea and its byproducts. As deposit depletion changes the stoichiometry of NOx/NH3, any predictive method becomes complementary to experimental studies on deposit formation. In the present work, we experimentally investigated deposit formation and its rate by a newer concept of usage of Stainless Steel (SS) foils considering temperature and flow rate as variables. According to numerical results, the droplet evaporation of UWS decreases as flow rate increases. For a fixed rate of UWS quantity of deposits decrease with increase in temperature and flow rate. Accordingly, structural changes are observed. Numerical values of time dependent deposit formation found slightly superior to the experimental values. The study revealed that deposit areas at low temperatures are comparable to numerical values. Phenomenological model is proposed to find deposit conversion factor for low temperatures (150–250°C), which helps in tuning of UWS dosage strategy to prevent NH3 slip. © 2016 Elsevier Ltd
Characterization and effect of using Mahua oil biodiesel as fuel in compression ignition engine
(2009) Kapilan, N.; Ashok Babu, T.P.; Reddy, R.P.
There is an increasing interest in India, to search for suitable alternative fuels that are environment friendly. This led to the choice of Mahua Oil (MO) as one of the main alternative fuels to diesel. In this investigation, Mahua Oil Biodiesel (MOB) and its blend with diesel were used as fuel in a single cylinder, direct injection and compression ignition engine. The MOB was prepared from MO by transesterification using methanol and potassium hydroxide. The fuel properties of MOB are close to the diesel and confirm to the ASTM standards. From the engine test analysis, it was observed that the MOB, B5 and B20 blend results in lower CO, HC and smoke emissions as compared to diesel. But the B5 and B20 blends results in higher efficiency as compared to MOB. Hence MOB or blends of MOB and diesel (B5 or B20) can be used as a substitute for diesel in diesel engines used in transportation as well as in the agriculture sector. © 2009 Science Press, Institute of Engineering Thermophysics, CAS and Springer Berlin Heidelberg.
Effect of Diethyl Ether on the Performance and Emission of a 4 - S Di Diesel Engine
(SAE International, 2004) Mohanan, P.; Kapilan, N.; Reddy, R.P.
Dimethyl Ether (DME), the methanol analog to Diethyl Ether (DEE), was recently reported as a low emission, high quality diesel fuel replacement. Literature review indicates that significant work is not carried out with respect to its performance analysis and in regard to pollution levels. In the present work, the effect of DEE on the performance and emissions of a four-stroke direct injection diesel engine have been studied. Tests were conducted on the diesel engine with different blends of DEE and diesel as fuel. Test results show that 5 % DEE blend gives better performance and low emissions compared to other blends of DEE and diesel fuel. Hence, 5 % DEE can be blended with diesel fuel to improve the performance and to reduce emissions of the diesel engine. © 2003 SAE International.
Effect of injection pressure on the performance and emission of diesel engine using blend of methyl esters of karanja oil and diesel as fuel
(2006) Kapilan, N.; Reddy, R.P.; Basavaraj, T.
There is an increasing interest in India to search for suitable alternative fuels that are environment friendly. This led to the choice of karanja oil as one of the main alternative fuel to diesel oil. Karanja Oil Methyl Ester (KOME) was prepared by transesterfication method. In the present work, blend of diesel and karanja oil methyl ester (B20) were used as fuel and the effect of injection pressure on the performance and emissions of a direct injected, four stroke, single cylinder diesel engine was studied. Results showed that for the B20 blend, the injection pressure of 200 bar results in better performance and lower emissions than other injection pressures. The brake thermal efficiency of karanja methyl ester at 200 bar was comparable with diesel. The engine emissions such as carbon monoxide, hydrocarbons, oxides of nitrogen and smoke emission were lower than diesel operation. Based on this study, it is observed that the B20 blend can be used as fuel in diesel engine with the injection pressure of 200 bar. Copyright � 2006 SAE International and Copyright � 2006 SAE Japan.
Effect of injection pressure on the performance and emission of diesel engine using blend of methyl esters of karanja oil and diesel as fuel
(SAE International, 2006) Kapilan, N.; Reddy, R.P.; Basavaraj, T.
There is an increasing interest in India to search for suitable alternative fuels that are environment friendly. This led to the choice of karanja oil as one of the main alternative fuel to diesel oil. Karanja Oil Methyl Ester (KOME) was prepared by transesterfication method. In the present work, blend of diesel and karanja oil methyl ester (B20) were used as fuel and the effect of injection pressure on the performance and emissions of a direct injected, four stroke, single cylinder diesel engine was studied. Results showed that for the B20 blend, the injection pressure of 200 bar results in better performance and lower emissions than other injection pressures. The brake thermal efficiency of karanja methyl ester at 200 bar was comparable with diesel. The engine emissions such as carbon monoxide, hydrocarbons, oxides of nitrogen and smoke emission were lower than diesel operation. Based on this study, it is observed that the B20 blend can be used as fuel in diesel engine with the injection pressure of 200 bar. Â© Â© 2006 SAE International and Copyright Â© 2006 SAE Japan.
Effect of injection time on the performance and emissions of LPG ME of mahua oil dual fuel engine
(2007) Kapilan, N.; Reddy, R.P.
There is an increasing interest in India, to search for suitable alternative fuels that are environment friendly. This led to the choice of non edible mahua oil as one of the main alternative fuels to diesel oil. Hence in the present work, Methyl Ester of Mahua Oil (MEMO) was used as pilot fuel and Liquefied Petroleum Gas (LPG) was used as primary fuel. A single cylinder, direct injection, four stroke, diesel engine was modified to work in dual fuel mode and the effect of injection time on the performance and emission of the dual fuel engine was studied. During tests, the engine was running smoothly with the MEMO. From the test results, it is observed that, at part loads, the advanced injection timing of 30� bTDC results in slight increase in brake thermal efficiency and lower exhaust emissions as compared to rated injection timing of 27� bTDC and retarded injection timing of 25� bTDC. Copyright � 2007 SAE International.
Effect of injection time on the performance and emissions of LPG ME of mahua oil dual fuel engine
(SAE International, 2007) Kapilan, N.; Reddy, R.P.
There is an increasing interest in India, to search for suitable alternative fuels that are environment friendly. This led to the choice of non edible mahua oil as one of the main alternative fuels to diesel oil. Hence in the present work, Methyl Ester of Mahua Oil (MEMO) was used as pilot fuel and Liquefied Petroleum Gas (LPG) was used as primary fuel. A single cylinder, direct injection, four stroke, diesel engine was modified to work in dual fuel mode and the effect of injection time on the performance and emission of the dual fuel engine was studied. During tests, the engine was running smoothly with the MEMO. From the test results, it is observed that, at part loads, the advanced injection timing of 30Â° bTDC results in slight increase in brake thermal efficiency and lower exhaust emissions as compared to rated injection timing of 27Â° bTDC and retarded injection timing of 25Â° bTDC. Copyright Â© 2007 SAE International.
Effect of injection timing and compression ratio on the performance and emissions of 2 -S SI engine with in-cylinder injection of methanol
(2005) Kapilan, N.; Reddy, R.P.; Prakash, T.P.
Producing and using renewable fuels for transportation is one approach for a sustainable energy for India, as well as the rest of the world. In the transportation sector, alcohols produced from biomass shows promise as an alternative fuel for spark ignited (SI) engines because of its high octane number. In the present work, methanol was used as an alternative fuel. In two stroke engines, In-cylinder injection of fuel results in excellent fuel economy potentional with lesser emissions. The objective of this work was to study the effect of injection timing and compression ratio on the performance and emissions of the engine. An air cooled, constant speed, single cylinder, two stroke, spark ignition scooter engine was modified to work in fuel injection mode. The performance of the modified engine was compared with the base engine. From the experimental results it was observed that the injection timing of 40�BEPC and compression ratio of 8.56:1 gives better performance and lower emissions than the base engine. Copyright � 2005 SAE International.
Effect of injection timing and compression ratio on the performance and emissions of 2 -S SI engine with in-cylinder injection of methanol
(SAE International, 2005) Kapilan, N.; Reddy, R.P.; Prakash, T.P.
Producing and using renewable fuels for transportation is one approach for a sustainable energy for India, as well as the rest of the world. In the transportation sector, alcohols produced from biomass shows promise as an alternative fuel for spark ignited (SI) engines because of its high octane number. In the present work, methanol was used as an alternative fuel. In two stroke engines, In-cylinder injection of fuel results in excellent fuel economy potentional with lesser emissions. The objective of this work was to study the effect of injection timing and compression ratio on the performance and emissions of the engine. An air cooled, constant speed, single cylinder, two stroke, spark ignition scooter engine was modified to work in fuel injection mode. The performance of the modified engine was compared with the base engine. From the experimental results it was observed that the injection timing of 40Â°BEPC and compression ratio of 8.56:1 gives better performance and lower emissions than the base engine. Copyright Â© 2005 SAE International.
Effect of using Mahua as an alternative fuel in diesel engine
(2009) Kapilan, N.; Ashok Babu, T.P.A.; Reddy, R.P.
There is an increasing interest in India, to search for suitable alternative fuels that are environment friendly. This led to the choice of non-edible Mahua Oil (MO) as one of the main alternative fuels to diesel oil in India. The objective of the present work is to use MO as a partial renewable alternative substitute for diesel in the agricultural diesel engine. Since the viscosity of the MO is high, it was blended with conventional diesel oil in various proportions (M5, M10, M15 and M20 on volume basis) and fuel properties of the blends were determined and compared with the diesel. Engine tests were carried out on a single cylinder diesel engine at varying loads (0%, 25%, 50%, 75% and 100%), without making any modification in the fuel injection system and the results were compared with the diesel. The M5 and M10 blends resulted in performance and emission characteristics comparable to diesel operation and also emits lower carbon monoxide, hydrocarbon and smoke emissions as compared to other blends. From the analysis, it is concluded that the MO can be partially substituted for diesel oil in the diesel engine, without making any modification in the hardware of the engine.
Evaluation of methyl esters of mahua oil (mahua indica) as diesel fuel
(2008) Kapilan, N.; Reddy, R.P.
There is increasing interest in India for suitable alternative fuels that are environment friendly. This search has led to mahua oil (MO) as one alternative for diesel fuel in India. Mahua oil methyl esters (MOME) were prepared by transesterification using potassium hydroxide (KOH) as catalyst and nuclear magnetic resonance (NMR) testing was done to determine the conversion of vegetable oil to biodiesel (MOME). The properties of MOME were close to those of diesel oil. Engine testing was conducted using a single-cylinder 4-stroke direct-injection, constant-speed compression-ignition diesel engine using MO, MOME and B20 as fuels. The engine ran smoothly with MOME and B20, but heavy smoke emissions were observed when MO was used as fuel. © 2007 AOCS.
Evaluation of properties and storage stability of Madhuca indica biodiesel
(Japan Oil Chemists Society yukagaku@jocs-office.or.jp, 2009) Kapilan, N.; Ashok Babu, T.P.; Reddy, R.P.
Mahua Oil (MO) is an underutilized non-edible vegetable oil, which is available in large quantities in India. In the present work, biodiesel was derived from the MO by the transesterification process. The fuel properties of the MO biodiesel were found to be within the limits of biodiesel specifications of many countries. The chemical nature of biodiesel makes it more susceptible to oxidation during long-term storage which leads to degradation of fuel properties that can compromise fuel quality. The effect of long storage condition on the stability of the MO biodiesel was studied in the present work. The biodiesel samples were stored in plastic containers at room temperature. The study was conducted for a period of 12 months and the test sample was kept in the darkness. From the experimental results, it was observed that the acid value and viscosity increases with the storage time, but the iodine value decreased with increasing storage time. This is due to the presence of the double bond in the molecule of the biodiesel which produce a high level of reactivity. This high level reactivity produces formation of hydroperoxides, soluble polymers and other secondary products. From the experimental results, a slight difference in the acid value, iodine value and viscosity of the MO biodiesel stored for a period of 30 days was observed. But after this period, the differences were significant. © 2009 by Japan Oil Chemists' Society.
Experimental investigation of esters of mahua oil as an alternative fuel for dual fuel engine
(2008) Reddy, P.B.; Kapilan, N.; Reddy, R.P.
In the present work, an attempt was made to use methyl ester of mahua oil (MEMO) as substitute for dieselin dual fuel engine. A four stroke single cylinder engine was modified to work in dual fuel mode. From the test results, it was observed that the MEMO could be used as pilot fuel in dual fuel engine. At lower loads, diesel gave higher brake thermal efficiency. But at higher loads, biodiesel resulted in brake thermal efficiency comparable with diesel and lower smoke and oxides of nitrogen emissions. From the test results, it was concluded that MEMO could be used as a substitute for diesel in dual fuel engine.
Experimental investigations on a compressed natural gas operated dual fuel engine
(2005) Kapilan, N.; Somayaji, C.; Mohanan, P.; Reddy, R.P.
In the present work, an attempt has been made for the effective utilization of Compressed Natural Gas (CNG) in diesel engine. A four stroke, single cylinder diesel engine was modified to work on dual fuel mode. The effect of CNG flow rate and Exhaust Gas Recirclulation (EGR) on the performance and emissions of the dual fuel engine was studied. The variables considered for the tests were different CNG flow rates (0.2, 0.3, 0.4, 0.5, 0.6 and 0.7 kg/hr), EGR (0%, 4.28%, 6.63 % and 8.12%) and loads (25%, 50%, 75% and 100 % of full load). From the test results, it was observed that the EGR rate of 4.28 % results in better brake thermal efficiency and lower CO and NOx emissions than other ERG rates at 25%, 50% and 75% of full loads. At full load, EGR rate of 8.12 % results in higher brake thermal efficiency and lower NOx emissions. Copyright � 2005by ASME.
Experimental investigations on a compressed natural gas operated dual fuel engine
(2005) Kapilan, N.; Somayaji, C.; Mohanan, P.; Reddy, R.P.
In the present work, an attempt has been made for the effective utilization of Compressed Natural Gas (CNG) in diesel engine. A four stroke, single cylinder diesel engine was modified to work on dual fuel mode. The effect of CNG flow rate and Exhaust Gas Recirclulation (EGR) on the performance and emissions of the dual fuel engine was studied. The variables considered for the tests were different CNG flow rates (0.2, 0.3, 0.4, 0.5, 0.6 and 0.7 kg/hr), EGR (0%, 4.28%, 6.63 % and 8.12%) and loads (25%, 50%, 75% and 100 % of full load). From the test results, it was observed that the EGR rate of 4.28 % results in better brake thermal efficiency and lower CO and NOx emissions than other ERG rates at 25%, 50% and 75% of full loads. At full load, EGR rate of 8.12 % results in higher brake thermal efficiency and lower NOx emissions. Copyright Â© 2005by ASME.
Improvement of performance of dual fuel engine operated at part load
(Universiti Malaysia Pahang editor.ijame@gmail.com, 2010) Kapilan, N.; Ashok Babu, T.P.; Reddy, R.P.
Rising petroleum prices, an increasing threat to the environment from exhaust emissions, global warming and the threat of supply instabilities has led to the choice of inedible Mahua oil (MO) as one of the main alternative fuels to diesel oil in India. In the present work, MO was converted into biodiesel by transesterification using methanol and sodium hydroxide. The cost of Mahua oil biodiesel (MOB) is higher than diesel. Hence liquefied petroleum gas (LPG), which is one of the cheapest gaseous fuels available in India, was fumigated along with the air to reduce the operating cost and to reduce emissions. The dual fuel engine resulted in lower efficiency and higher emissions at part load. Hence in the present work, the injection time was varied and the performance of the dual fuel engine was studied. From the engine tests, it is observed that an advanced injection time results in higher efficiency and lower emissions. Hence, advancing the injection timing is one of the ways of increasing the efficiency of LPG+MOB dual fuel engine operated at part load. © Universiti Malaysia Pahang.
Improvement of performance of vegetable oil fuelled agricultural diesel engine
(2009) Kapilan, N.; Ashok Babu, T.P.A.; Reddy, R.P.
In recent years, there has been a considerable effort to develop and introduce alternative renewable fuels to replace conventional petroleum based fuels. This led to the choice of non edible Mahua Oil (MO) as one of the main alternative fuels to diesel oil in India. When MO was used as fuel in the diesel engine, it results in lower thermal efficiency and higher smoke emission due to its higher viscosity and lower volatility. Hence in the present work, Liquefied Petroleum Gas (LPG) was inducted along with the air and the LPG supply was varied from zero to the maximum value that the engine could tolerate. The engine tests were conducted on a single cylinder diesel engine, which is used in the agricultural machinery. The engine test with MO+LPG was compared with the LPG+MO biodiesel (MEMO) and Diesel+LPG. From the engine results it is observed that the MO+LPG dual fuel mode operation results in performance close to the MEMO+LPG. The MO+LPG operation results in higher brake thermal efficiency and lower smoke emission as compared to the MO operation. From the present work, it is concluded that the underutilized and non edible MO can be used as a renewable alternative fuel for the diesel engine, for the development of rural economy and for the energy security of India.
Influence of diethyl ether on the performance and emissions of a compression ignition engine fuelled with biodiesel
(Penerbit Akademia Baru, 2020) Kapilan, N.; Prabhu S, S.; Vasudeva, M.
India is one of the major importers of petroleum products and hence government of India has taken several steps to find suitable alternative fuels to the fossil fuels. The biodiesel derived from non-edible oils is considered as an immediate substitute for the fossil diesel. In this work, biodiesel was produced from non-edible honge oil and used as substitute for the diesel. The engine tests were carried out on a diesel engine which is most widely used for agricultural purpose. From the engine tests, we observed that the diesel engine performance with biodiesel is lower than the diesel due to lower volatility and slightly higher viscosity of the biodiesel. Hence, the objective of this work is to study the impact of diethyl ether (DEE) on the performance of the engine. The engine tests were conducted on a single cylinder, water cooled, compression ignition engine at steady state condition. The engine test results showed an increase in brake thermal efficiency and reduction in engine exhaust emissions such as CO, HC and smoke with the addition of DEE as an additive. From this work we conclude that the DEE can be used as an ignition improver for the honge oil biodiesel. © 2020 PENERBIT AKADEMIA BARU - All rights reserved.
Methyl esters of Mahua oil as an ecofriendly fuel in heavy duty vehicles
(Chemical Publishing Co., 2008) Kapilan, N.; Krishna; Reddy, R.P.
In this investigation, Mahua oil methyl ester (MOME) was prepared by transesterfication using potassium hydroxide. According to the ASTM procedure, several tests were conducted to characterize mahua oil in relation to diesel oil. Various physical, chemical and thermal properties such as viscosity, flash point, fire point and calorific value were evaluated. From the analysis, it was observed that the properties of mahua oil methyl ester are close to diesel oil. To evaluate the mahua oil methyl ester as a fuel for diesel engine and dual engine, it was used as a fuel in a single cylinder, four stroke, direct injection, constant speed, compression ignition diesel engine and dual fuel engine. From the experimental results, it was observed that the mahua oil methyl ester result in performance and emissions close to diesel operation.